chester



Ibeing made to the accompanying drawings.

- have heretofore been made by winding insulatv fiat bar is generally employed to connect the port,

UNITED STATES PATENT' rtree@ CHARLES T. CHESTER or new YORK, n. Y.

IMPROVEMENT iN ELECTRO-MAGNETS.

To all whom t 'may concern .s

Be it known 'that I, CHARLES T, CEsrne, of thecity, county, and State of New York, have invented'anew and improved Mode of Constructing Electro-Magnets and i do hereby declare that the following is a vfull and accurate description ofthe said invention, reference M yinvention relates to electro-magnets principally used to impart motion to an armature, as in telegraphinstruinents. Such magnets ed wire upon the soft-iron cores, with anges so placed upon the iron cores as to conne the wire. A fiat bar of soft iron unitesthe cores of two such straight electro-magnets, and this entire magnet to a brass support;'bi1t'as Ythissupport is thus only at one end ofthe magnet the weight of the coils requires that sombe additional support should be placed forward, and this support is almost always made to embrace the Wire. This mode of construction is objeci tionable for the following reasons: first, because it does not admit of removing the cores for annealing without unwindingthe wire and removing, and generally destroys the anges; second, because it does not admit of relative adjustment of the helices and cores for tl e purposeof varying and regulating the ower ot the magnet when required by .'ariat'onV of the current; third, because by the mode adopted of securing the magnets and helices to the instrument the wire is liable to be crushed, 85o.

The nature of my said inventionl consists in several improvements in construction and arrangement, designed to obviate the above-men tioned objections. 'They are as follows, viz:

First, in constructing' the helicesindependent of the cores by winding them on hollow reels or spools vof hard rubber or other suitable material and placing within suitable cores of soft iron, the core ybeing confined so as to have no moi/grithn the helices, by reason or" the actie the current.o

Secondly, in a means of ad j ustingtlie position relatively of the cores within the helices. This I effect by a setscrew and spring operating antagcnisticali y to each other on the cores, the helices having an independent means of sup- Thirdly', to a mode of supporting the helices l vSrc., and a well-known fabric independently ofthe cores and without possi ble injury to the wire.

To describe more particularly the constrncv tion, reference being made to accompanying' drawings, &c.:

l wind my helices upon spools ot' hard rubber-the'substance employed in making combs, possessing very high insulating properties. The cylinders of these spools are` as thin' as possible. Their anges are thick enough to -allow the outerV`A` portion of their peripheries to be cut awa-y ina car-wheel, Fig. l, A. The substance cut `rmly fastened together. This brass I will refer to as double ring.

The spool fianges are made accurately to fit the rings by a .simple machine, and a double ring being` provided for each end of the spools as vsoon as the spools are set in the rings and the double rings drawn together in a direction parallel to the spool-axes,'the structure is complete and firm and ready to be fastened down to any'rproperbase. yIt is only necessary to wind the spools with insulated wire and the v.electro-n1agnet is complete, except its iron core.

This core is made of the finest and softest iron bentv into U form. Whenproperly iinishedit 'will exactly pass into and lill up the hollow spoolcylinders. The cur-ve will project semicircnlarly from the anges, Fig. 3, G. A small piece of brass, easily removable, is now at tached under' the center of this curve of the iron core. This brass, bein g drilled and tapped in a direction parallel with the axes of the spools, receives a screw, s, when the screw is driven in by turning' its milled head till its point presses against the double ring. The iron core is forced slowly out from the spools. A strong short spiral spring, a, extending between and fastened to the double ring and core, pulls the core in again as soon as the pressure ofthe screw is withdrawn. Thus, be-

tween the screw-pressure and the spring drawing, the core is moved slowly, tirml y, and steadily in and out vef the spools.

fan armature receive the power or" the electro-magnet, itis evident that the power will be least when the core is pressed out and s y estese est when it is drawn in so es to touch the arme.-

' ture. B y this combination of .screw and spring any hesitation to move (and thus any inaccureey of adjustment) is prevented. In other Words there is no deed-point when the eures do not move. This deed-point must exist where s screw alone isdepended onfor adj ustnnent.

lt will be seen by thisdeseription, rst, that the core which in relegraphing continuously always enquires some fixed und permanent magnetismyto the greet annoyance oi'telegrephie operators, may be easily removed and rennneeled d repleoed The ooreis notheinmered or Wrought in enyn'ey after leaving the unneelingproeess. Secondly,thepeouliardoubley ring support, grasping only' the herdrubber spooi-anges,'does not press upon the tine Wire in r@my Way.

in the eeminon Way of' supporting helices the ,mere rmly they are held the more is the Wire crushed, end'lightning is always sure to ind out this week. spot irst. 0f more then two hundred magnets constructed by me in this method none have yet7`to my knowledge,

been burned by lightning. 'The method 'of winding the Wire on herd-rubber spools also secures the best linsulation ol.' the Wire from the iron cores and facilitates repairs, ese new helix een be put in the place of en injured one.

What I' eleim es my invention und improvement in magnets used to impart motion to armetures, as in telegraphinstruments, is as fol! lows, viz: y i l l.' In combination with cores eonined so as to prevent-tbe action of the current through e surrounding helix from imparting motion to them, helices Wound on spools of hard' rubber or other suitable materiel surrounding the cores and so arranged that the cores may be removed from them when requisite, substantially as describednd substantially for the purposes set forth.

2 Hoidingmoving, und adjusting the oore's by ineens of the screw und spring, substrintiztlly us describedu 3. Coupling end supporting thehelioei spools bythe deuble rings, substantially es described.

CHARLES T. CHESTER.

Witnesses:

Ti-ros. L. @Ensign-n, Joni-I SIDELL. 

